Yes, it is just a concession. Have decided already to SORN mine this winter. The (ex) government has won, one less V8 on the road. Well, actually no, just means that the other V8 gets used more and I save money.
Note: 2009 and 2010 concession
All cars with a CO2 value over 225 and first registered between 1 March 2001 and 23 March 2006 will be capped at band K during 2009 and 2010